Add bitcoind P2P monitoring to rewards portal

[ethgr0wth]

Summary

• add bitcoind-style P2P socket probes to the health monitor and fold the results into uptime scoring and reward distribution
• persist combined RPC/P2P metrics in Redis, expose them through the API, and guard admin dashboards with consistent defaults
• surface RPC and P2P status in the operator/admin UI and document the new configuration toggle

Testing

• PYENV_VERSION=3.11.12 python -m pytest ambassadors/node-operator-rewards-portal/backend/tests/test_rewards.py

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https://chatgpt.com/codex/tasks/task_e_68f195a2ef54833387184a412e589db3